If you don't interact with people, how can you tell they misgender or clock you? People stare all the time. People stare at me, people stare at my mom, my sister in law, my wife. People just stare. Especially if you wear bright colors like red, salmon or pink.
The random person on the street doesn't bother me as much as the retail store clerk or restaurant employee who will blurt out a "sir." There are even people I know who have gotten clocked and blatantly laughed at, and it was triggered by voice.
The thing is that you cannot know what J. random street person is thinking. And in most cases unless you have obviously strong masculine features the most they will be is unsure of your gender. They will have doubt in their mind but the doubt is double edged - they aren't sure if you're a woman, but they aren't sure if you're a man either. When you have to talk it will swing the needle in whichever direction and if you do it right it will be in the female direction.
That is why I fully stand by my statement. Voice and mannerisms are key. Looks are only secondary.
However, all of these things make up a complete picture.
As for telling people, I don't. Not even people I work with beyond those who knew when I went full time, or those who don't know and mistakenly called me by my old name. But new people I don't tell. Maybe they figure it out themselves, maybe they don't. It's really nobody's business. I am not an activist and my mission is simply to live my life.